Nov 20 2008
Carbon dioxide (CO2) compression is a necessary part of any carbon capture process and Air Products' oxyfuel technology has optimized the compression process to remove impurities to an acceptable purity level in the gas to make carbon sequestration possible, Vince White, a research associate in the Energy Technology group at Air Products (NYSE: APD), told attendees today in a presentation at the 9th International Conference on Greenhouse Gas Control Technologies (GHGT-9) in Washington, D.C. The Conference, organized by MIT in collaboration with the IEA Greenhouse Gas R&D Programme, was sponsored largely by the United States Department of Energy.
White said oxyfuel technology can reduce the cost of capturing CO2 for the power industry and that Air Products has specifically focused on the purification of the resulting oxyfuel combustion flue gas, developing a robust process for the efficient removal of trace impurities. The reduction of these impurities to an acceptable purity level is necessary before any carbon captured could be transported for underground storage. White described Air Products' patented sour compression technology, which uses a staged compression process to optimize pressure, hold-up and residence time to allow removal of impurities including sulfur dioxide, nitrous oxides, mercury, and other heavy metals from the CO2 containing gas during the compression process. This allows cost savings in the oxyfuel combustion process and minimizes the content of these components in the sequestered CO2.
Air Products' oxyfuel sour compression technology has been demonstrated in experimental work carried out by Imperial College London with actual flue gas from Doosan Babcock's 160kW coal-fired rig in Renfrew, Scotland, as part of the Oxycoal-UK Project. White presented the findings of this work to the Conference audience from a paper entitled "Purification of Oxyfuel-Derived CO2" which he co-authored with Laura Torrente Murciano and David Chadwick, both of the Chemical Engineering Department at Imperial College, and David Sturgeon of Doosan Babcock Energy Limited.
"The experimental data collected by Imperial College demonstrates the theory of this technology which, combined with previous findings that nitrogen, argon and oxygen are easily removed, shows that oxyfuel CO2 capture technology can successfully remove multiple impurities. This is essential to being able to deliver CO2 for sequestration that meets the acceptable purity level. The data shows that impurities removal can be achieved during compression and without more expensive and complex flue gas de-sulfurization units and de-NOx units," said White. "The ability to achieve this at lower costs is encouraging to industries with large scale CO2 emissions."